On Mon, Jul 13, 2015 at 10:34 PM, Fujii Masao wrote: > On Fri, Jul 10, 2015 at 10:06 PM, Beena Emerson wrote: >> On Tue, Jul 7, 2015 at 2:19 PM, Michael Paquier wrote: >> >>> Something like pg_syncinfo/ coupled with a LW lock, we already do >>> something similar for replication slots with pg_replslot/. >> >> I was trying to figure out how the JSON metadata can be used. >> It would have to be set using a given set of functions. > > So we can use only such a set of functions to configure synch rep? > I don't like that idea. Because it prevents us from configuring that > while the server is not running.
If you store a json blob in a set of files of PGDATA you could update them manually there as well. That's perhaps re-inventing the wheel with what is available with GUCs though. >> Is JSON being preferred because it would be ALTER SYSTEM friendly and in a >> format already known to users? > > At least currently ALTER SYSTEM cannot accept the JSON data > (e.g., the return value of JSON function like json_build_object()) > as the setting value. So I'm not sure how friendly ALTER SYSTEM > and JSON format really. If you want to argue that, probably you > need to improve ALTER SYSTEM so that JSON can be specified. > >> In a real-life scenario, at most how many groups and nesting would be >> expected? > > I don't think that many groups and nestings are common. Yeah, in most common configurations people are not going to have more than 3 groups with only one level of nodes. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
